Find every subdomain
of a domain.

Every hostname under a domain that ever appeared in a public TLS certificate — with certificate counts, first/last seen and live DNS status.

4 hosts · 228 ms

HostCertsFirst seenLast seenDNS
alive-project.com 2 2025-07-03 2026-07-16 ok
*.alive-project.com 2 2025-07-03 2026-07-16 —
link.alive-project.com 3 2026-07-16 2026-09-23 ok
help.alive-project.com 8 2026-05-08 2026-08-20 ok

Programmatic access, with DNS A records: API GET /v1/hosts/alive-project.com (API key for paging).

Shown here: hostnames with a certificate that is valid now or expired within the last 90 days. The full history since 2013 — hostnames whose last certificate expired earlier — is a Pro plan method: GET /v1/hosts-history/alive-project.com.